Part 3: Building the headband

Alright, this is the final steps before you are ready to play your own game of laser tag! The next step is going to require that you have access to a soldering iron, some solder, and (hopefully) a third hand tool to help hold things together while you solder them. 

If you don't know how to solder, there is a great tutorial here.

Assuming you have everything you need, get your soldering iron and apply a little bit of solder to the RGB LED strip, where you see a small copper pad with a + sign next to it. 

Next, apply a little bit of solder to a white wire. This wire should be about three feet long (the minimum distance should be the distance from the top of your head to the tips of your fingers. This wire is going to go from your head to your hand when you are running around with the device).

Next, place the wire next to the RGB strip so that the wire is touching the solder that was already applied to the RGB strip.

Solder the wire to the RGB strip by heating the wire and the solder on the RGB strip (and applying a little more solder, as necessary). When it's done, you should have a connection that you can tug on lightly, and it won't break.

As you are doing this, there is a chance that you will mess up. That's ok. If you can, unsolder the connection and try again. If you try again and the soldering pads start looking black, try scraping them off to clean them. If you've made a terrible mess and nothing can be salvaged, just cut the RGB LED shorter (cut along the part with the scissor icon, and try soldering onto that).

And messing up isn't a big deal. It's happened to me too. Just cut the RGB strip a little shorter, and try again.

Assuming the white wire is connected, you are now going to do the same thing to connect a green wire to the small copper pad with a G next to it by applying solder to the pad, then to the wire, and then soldering them together. The green wire should be much shorter than the white wire. The Green wire needs to be  long enough to go from your right ear to the top of your head, which is probably about six inches. You can use a ruler or a measuring tape to measure, and you can always make it longer and then cut it shorter later if you want to be on the safe side.


Next, we are going to connect a red wire (also as long as the length from your ear to to the top of your head) to the copper pad with an R next to it. Again, this one should be the distance between your ear and the top of your head, or about 6 inches.


Finally, connect a blue wire (again, as long as the distance from your ear to the top of your head) to the copper pad with a B next to it. Again, this one should be the distance between your ear and the top of your head, or about 6 inches.

Once you have all of the wires connected, wrap them all in a piece of duct tape or heat shrink. That will help hold them in place.

Next, measure the distance around your forehead, and cut the hook tape (not the one with the soft side. The one with the pokey side) of the hook and loop fastener to be about 1 inch shorter than the distance around your head. This is going to sit on your forehead, so measure around your head as if you were wearing a hat or a headband. For me, the meausrement comes out to about 9 inches.

Next, cut about two inches of the loop fastener (the one with the soft side) and stick it onto one end so there is about an inch hanging off of the side. This is going to allow you to connect the hook and loop band around your head like a headband.

Go ahead and put the headband you just made on your head, securing the hook and loop fastener over your right ear. Next, measure the distance on the headband from where it sits on the front part of your forehead all the way to the back of your head. Cut another piece of the loop fastener (with the soft side) to that length, and connect it to the headband from the front of your forehead to the back of your head. This essentially is creating a strap on top of the headband.

Take the headband off. It should now fit your head and look like this:


Next, place the headband down with the part used to attach the headband to your head is on the left side. Take more of the loop fastener material (with the soft side), and cut two small pieces (about 1-2 inches) and one long piece (about 3 inches) and connect them to the hook parts of the headband (as shown below).

 This makes is so that there are smooth parts you can attach the RGB LED strip to. Take the RGB LED strip and peel off the paper backing (it should be sticky underneath).

Starting from next to the piece that connects the headband (see picture), stick the RGB strip onto the headband so that it goes around the bottom of the headband. (Note, if the RGB strip is longer than the headband, cut is shorter before sticking it on). 

 The RGB strip should end on or before the piece used to connect the headband.

Once the RGB strip is in place, bend all the wires up towards the part of the headband that goes over your head, and then tape them to the headband.


Next, on the top band that goes over your head, peel back the plastic on the strip (you'll need to cut it with scissors to remove it) to reveal the sticky part underneath. You want to do this in the middle, so that it is over the middle of your head when you are wearing it. Peel enough off to fit the solderless breadboard you made with the infrared sensors.

 Stick the solderless breadboard onto the top of the headband so it's perpendicular to the headband, and then tape it to the headband (see image below). Do not put tape on the sensors. Put tape across the black wire that goes from the infrared receivers to the transistors (see pictures below).

After the breadboard is taped down, grab the blue wire that was soldered to the RGB LED strip. Connect the blue wire to 22-a.


Next, take the green wire attached to the RGB LED strip, and connect it to 18-h.

Next, connect the red wire from the RGB LED strip to 22-f.

 At this point, we have connected the RGB Strip to the sensor package, and have finished the headband. The last step is to connect the headband to the arduino, and then we are done!

Take the long white wire that connects to the RGB LED (the one connected to +). Connect it to the arduino over the female header pin with the letters "Vin" under it. It's the one on the right side of the header pin (see picture below. this connects it to the battery power on the arduino).

That white wire sets the minimum distance we need to make the other wires that connect the arduino to the headband.

Next, we need to cut a red wire to connect the sensor package to the arduino. Make this one longer than the white wire that connects to the RGB LED strip to the arduino. It needs to go from the side of the top of the headband to the arduino (this one goes from the arduino to the infrared receivers).  Remember this length, as you are going to make a few wires this lenght. For me, I cut the wire so that it's the distance from the tips of my finders to the top of my head. Which is about three and a half feet. Plug the red wire into the arduino where the header pin says, "5V", which is the third hole from the left.


Next, plug the other side of the red wire into 4-j on the headband.

We are going to make connections between the arduino and the solderless breadboard for the rest of this tutorial, so cut all the wires to be the a little longer than the red one you just made.If you go to plug them in, and they are a little long, you can always cut them shorter. You can't cut them longer.

Next, cut a black wire and connect it to the right of the red wire, over one of the header pins labeled, "GND" on the arduino.

 Now, wrap the black wire around the red wire a few times going from the arduino to the other breadboard. Maybe 20 or so. This keeps the wires together so they aren't a mess later. You are going to do this with all the wires so that they stay together. Don't wrap it around the white wire yet. You will do that later.

Next, plug the black wire into 5-j on the headband (wire is pictured not plugged all the way in so you can see more clearly where it goes). 


 Next, cut a long yellow wire and plug one end into pin 7 on the arduino, and the other end into pin 6-j on the headband (wire is pictured not plugged all the way in so you can more easily see where it goes).

 We are now going to start connecting the RGB LED on the board with the RGB light strip that goes on your head. Connect a green wire one hold to the left of the RGB LED, on the bottom row.

 Wrap the wire around the other ones, and plug the other end into 21-i (again, the image below doesn't show the wire plugged all the way in to show where it goes).

 Next, plug a blue wire on the row above the green wire on the arduino breadboard (plugging in one hole above and one to the left).

Wrap all the wires together as you bring the wire over to the headband. The wires should start looking pretty festive with all the colors.

 Plug the other end of the wire into 25-b.

Next, go two rows up on the arduino breadboard and connect a white wire to the left side of the RGB LED (wire shown below not plugged in all the way)

Next, wrap the wire around the others and plug the other end into 25-j.

Assuming that you haven't wrapped the white wire coming from the RGB LED band into the other wires (if you have, skip these next few steps), unplug the white wire connected to the RGB LED (the long one on the headband that we haven't connected yet),

Wrap it around the other wires near the top of the headband, and then wrap around the other wires going back to the arduino. This helps keep it from getting pulled out.

Next, plug it into the arduino over the header pin that says "Vin" (again, the wire is not shown plugged all the way in). 

At this point, you are almost done with putting everything together. The last thing you need to do is plug a yellow wire as shown below:

The wire connects on the left side of the arduino in the header pin labeled 0, shown below.


Plug the other end of the yellow wire into the header pin on the bottom with a "5V" under it.


And that's it! You now have built the laser tag device! Here's what it looks like when it's done.

The device should already be programmed with laser tag. Plug in the 9 Volt battery to the 9 Volt battery connector, and then plug the plug end into the arduino, and then presto! You can play laser tag! To turn the device off, unplug the battery.

 And that's it! Now, you can play laser tag!

If you want to go the extra mile and secure the wires so they don't fall out during play, click here.

If you want to learn how the devices work so you can start playing, click here.